The present invention pertains to an arrangement of a conveying track for containers, which are conveyed on the conveying track, are to be filled with articles or bulk material in a filling station via a feed hopper and are located in the filling position, and especially to the part of an automatic commissioning unit transfer station which feeds the shipping containers to the filling station, positions them under the feed or transfer hopper for the duration of the transfer of the articles or products and subsequently removes them from the filling station.
According to the state of the art, the containers are moved in the area of the automatic commissioning unit transfer unit via a continuously running conveyor belt. The separation of the arriving containers is brought about by a clamping device arranged in front of the transfer station, which grasps the container located in the front and allows it to move farther only shortly before the filling station becomes free. A second clamping device, which grasps the arriving container and fixes it until the conclusion of the filling in the correct position, is arranged directly under the filling or transfer hopper arranged downstream of the first clamping device on both sides of the conveyor belt. The filled container is subsequently let go, carried continuously by the driven conveyor belt in a frictionally engaged manner and is removed from the transfer area. The container change time and consequently in many cases the throughput capacity of the entire automatic commissioning unit thus depend on the velocity with which the containers are moved forward cyclically on the conveyor belt in a frictionally engaged manner.
The object of the present invention is to provide an arrangement of the type described in the introduction, which permits a faster movement of the commissioning containers in the area of the filling station with simple means and also permits the accurate positioning of the containers in the filling position under the filling hopper.
According to the invention, an automatic commissioning unit arrangement is provided with a conveying track to and from a filling station for conveying the containers. The containers are open at the top and are filled with articles or bulk material via a feed hopper in a filling station in a stopped filling position. The essence of the present invention is that the conveying track has, in the immediate area before, in and/or after the filling station, at least one circulating toothed belt or chain drive with a separate intermittent adjusting drive and container-engaging knobs located at spaced locations from one another, which can be caused to engage the containers arriving on the conveying track, which are open at the top, and by which the containers can be moved, separated, both into the filling position and, after filling, can be removed from the filling position in an accelerated and cyclic manner and can be optionally moved again into the conveying track by means of the adjusting drive.
The circulating toothed belt or chain drive is preferably arranged on both sides of the conveying track and is axially symmetrical to the conveying track.
In a variant of the embodiment, a single circulating toothed belt or chain drive may be provided in the immediate area before, in and after the filling station with preferably six container-engaging knobs distributed equidistantly from one another over the run.
A single through conveying track may be provided before, in and after the filling station, preferably as a belt conveyor or belt drive, or an interrupted input-side (and/or output-side) conveying track may extend into the filling station and overlap the toothed belt or chain drive in the longitudinal direction of conveyance.
However, the conveying track may also be interrupted, as an alternative, in the area of the circulating toothed belt or chain drive without overlapping the latter, and have a separate belt conveyor or belt drive with a separate drive.
The belt conveyor or belt drive expediently has a stationary upper sliding surface in the area of the filling position, and the belt conveyor or belt drive may be offset downward in parallel via deflecting rollers in the area of the sliding surface.
In another embodiment variant, the conveying track may be interrupted in the area of the circulating toothed or chain drive and have two additional belt conveyors or belt drives with separate drives of their own, wherein one belt conveyor or belt drive is arranged in front of the filling position and the other belt conveyor or belt drive is arranged after the filling position and a stationary sliding surface is arranged in the area of the filling position.
In front of the toothed belt or chain drive, the input-side conveying track preferably has a container-blocking mechanism, which can be placed in the path of movement of the containers being conveyed and can release the path of movement of the containers being conveyed.
The input-side conveying track may be not only a through conveyor belt, but also a driving roller conveyor or an accumulating roller conveyor.
A driving roller conveyor is defined as a frictionally engaged conveyor with continuously driven rollers, which is under the pressure of the objects being conveyed. The frontmost conveyor strikes the above-mentioned container-blocking mechanism in the accumulated position. The accumulated containers lie at closely spaced locations from one another in the frictionally accumulated state.
A (lifting) accumulating roller conveyor is defined as a conveyor not subject to the pressure of the objects with driven rollers, in which the (lifted) containers are at defined spaced locations from one another in the accumulated state and in which the above-mentioned container-blocking mechanism is not absolutely necessary, but it may be advantageously provided for a more accurate positioning.
The container-blocking mechanism is preferably a pneumatically pivotable or displaceable locking bar and is arranged especially between two rollers at the end of the input-side conveying track, which is now preferably designed as an accumulating roller conveyor.
Both rollers may have a larger diameter than the other rollers of the conveying track, in which case they form so-called accelerating rollers. The function of the accelerating rollers arises from the fact that a correspondingly higher circumferential velocity of the last two driving rollers is generated compared with the other rollers due to the difference between the diameters of the drive (small diameter) and the driven rollers (larger diameter), and this higher circumferential velocity removes the frontmost container from the adjacent container in an accelerated manner during the release of the blocking mechanism and brings about a distance from the latter container, so that the released blocking mechanism can again move into the blocking position before the adjacent container is moved on. The frontmost container is thus xe2x80x9cseparated.xe2x80x9d The distance generated between the containers is sufficient to allow time, especially for a photoelectric cell, to process a signal for the actuation of the pneumatic blocking mechanism before the arrival of the next container.
Both of the rollers located in the immediate vicinity of the container-blocking mechanism may also have a drive of their own. In this case, this drive can be operated at a higher speed of rotation than the drive of the other rollers in order to establish the abovementioned distance between the containers, and all rollers may have the same diameter.
Thus, the essence of the present invention is that the frictionally engaged carrying of the containers according to the state of the art discussed in the introduction is replaced with a positive-locking carrying, namely, by the container-engaging knobs provided according to the present invention in conjunction with a (slip-free) toothed belt or chain drive with a separate dynamic drive motor, which make it possible, on the one hand, to accurately position or stop the containers in front of or in the filling station while the conveyor belt continuously runs at the same time, and, on the other hand, to grasp behind a stopped container and especially a container filled with articles and to rapidly accelerate same from the stopped position, doing so with the engagement of a container-engaging knob on the rear side of the container, which faces away from the direction of conveying. Since the positioning of the containers takes place in a positive-locking manner rather than by clamping the containers as according to the state of the art, not only comparatively stable containers, e.g., those made of plastic, but also containers made of a more fragile material, e.g., pasteboard, may be used according to the present invention.
It is obvious that the distance in the direction of conveying between two container-engaging knobs is more than half of the length of the container, and preferably slightly more than the length of the container.
It is also obvious that if two lateral, intermittently operated toothed belt or chain drive halves with continuously operated conveyor belt located between them are provided, the distance between two associated container-engaging knobs of each half, which knobs are located at the same level in the direction of conveying, is smaller than the width of the container, so that a container is not rotated but longitudinally offset by the associated engaging lateral knobs during the conveying.
The drive of the toothed belt or chain drive is preferably a dynamic electric motor operator, which is put into operation intermittently by one knob pitch. The belt or the chain is consequently moved farther by one knob pitch, with a comparatively high acceleration, and is subsequently allowed to stop for the duration of the filling of the container under the feed hopper, while the conveyor belt of a through conveying track or of a separate belt drive or conveyor belt located in between continues to move forward. Due to the accelerated feed and removal with simultaneously accurate positioning of a container under the feed hopper, the container change time and consequently the throughput capacity of the entire plant can be nearly doubled compared with the state of the art mentioned in the introduction, doing so without a great effort. The compact design of the conveying track remains unaffected hereby.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.